How to Choose Between Investment Platforms

Choosing between investment platforms can feel overwhelming — there are dozens of brokers and platforms in the UK market, each with different fee structures, minimum deposits, and feature sets. The right one depends on three things: how much you're investing, what you want to invest in, and how hands-on you want to be. A platform that's brilliant for a £100,000 portfolio might be expensive for £5,000. This guide shows you how to compare platforms on the factors that actually matter.

Types of Investment Platforms

UK investment platforms broadly fall into three categories:

Execution-only brokers are the cheapest and simplest. They give you access to stocks, funds, and ETFs, but no advice. You pick what to buy; they just execute the trade. Good if you know what you want to invest in and prefer to research yourself.

Robo-advisors take your risk tolerance and time horizon, ask a few questions, and build a diversified portfolio for you automatically. They rebalance regularly (typically quarterly or annually) and charge a percentage fee — usually 0.25% to 0.75% per year. Good if you want "set it and forget it" without having to make individual investment choices.

Wealth management and full-service advisors offer bespoke portfolios and personal advice, typically starting at £50,000+ in assets. They charge 0.5–2% per year or a fixed fee. Good if you have significant assets and want one-to-one guidance.

For most people starting out or investing up to £100,000, execution-only brokers or robo-advisors are the right fit.

Platform Fees: Flat vs Percentage

This is where platform choice really hits your wallet. Fee structures fall into two camps:

Flat-fee platforms charge you a fixed amount per year (e.g., £60–150) regardless of how much money you have invested.

Percentage-based fees charge you a percentage of your assets under management, typically 0.25–1.5% per year.

Here's how they compare:

Portfolio size	Flat-fee platform (£100/year)	0.5% percentage platform	0.75% percentage platform
£5,000	£100 (2.0%)	£25 (0.5%)	£37.50 (0.75%)
£10,000	£100 (1.0%)	£50 (0.5%)	£75 (0.75%)
£25,000	£100 (0.4%)	£125 (0.5%)	£187.50 (0.75%)
£50,000	£100 (0.2%)	£250 (0.5%)	£375 (0.75%)
£100,000	£100 (0.1%)	£500 (0.5%)	£750 (0.75%)

As you can see, flat-fee platforms win when you're starting small (under £20,000). Once your portfolio grows past £20–30k, percentage-based platforms become cheaper. Some platforms offer tiered fees — flat up to a certain amount, then percentage beyond — to capture both markets.

On a £10,000 portfolio growing at 7% per year, the difference between paying 0.5% and 0.75% is just £25/year — not huge in absolute terms. But over 30 years, even small fee differences add up. That £25/year at 7% growth becomes roughly £2,500 in missed wealth by retirement. Compound interest rewards starting early, and platform fees are a hidden drag on that compounding.

Other Fees to Watch

Annual platform fee is only part of the picture. Most platforms charge extra for:

Trading fees (per trade) — some charge £5–10 per stock trade, others charge nothing for ETFs and mutual funds. Buy-and-hold investors don't feel this; frequent traders do.
Dealing spreads — the difference between buy and sell prices. Thinly traded funds or international stocks can have wide spreads (0.5–2%), costing you at entry.
Fund fees (expense ratio) — the fund itself charges a fee, independent of the platform. A passively-managed FTSE 100 fund costs 0.1–0.2% per year; actively managed funds cost 0.5–1.5%. These sit inside the fund price and you don't see them line-by-line, but they compound over time.
Exit fees or early withdrawal penalties — rare now, but some platforms penalise you for closing accounts or moving money out.

Always check the full fee breakdown before opening an account. Platforms are required by law to show you a detailed fee illustration. The FCA's Financial Services Register lists all regulated platforms and their fee structures.

Features and Access

Beyond fees, platforms differ in what investments they offer and how easy they are to use:

Investment range: Some platforms give you thousands of funds and ETFs; others limit you to a smaller curated list. Most investors don't need thousands of choices — a good platform offers at least 500–1,000 funds across different asset classes.

Minimum investment: Some platforms require £1,000 to open an account; others let you start with as little as £100 per month. If you're investing small amounts regularly, look for platforms that don't penalise monthly contributions.

Tax-efficient wrappers: UK platforms should support ISAs (tax-free growth up to £20,000/year) and SIPPs or pensions. The ISA wrapper alone can save you thousands in tax over a lifetime. Make sure your chosen platform supports your preferred tax wrapper.

Rebalancing tools: Some platforms automatically rebalance your portfolio (selling winners, buying losers, to keep your allocation on track). Others make you do it manually. Regular rebalancing is important, but if you pay trading fees every time, you'll avoid doing it. Look for platforms with automatic or free rebalancing.

User interface and research tools: A platform is only useful if you'll actually use it. Some offer excellent charts and research; others are barebones but faster to navigate. Spend 15 minutes on each platform's demo to see if it feels intuitive.

How to Compare Platforms for Your Situation

Start with your specific situation, not a generic ranking. Ask yourself:

How much are you investing to start? If you have £5,000, a flat-fee platform is probably cheaper. If you have £50,000+, look at percentage platforms.
What do you want to invest in? If you want individual stocks, you need a stock broker. If you want funds and ETFs, most platforms work. If you want US stocks, check currency conversion fees.
How often will you trade? Buy-and-hold investors don't care about per-trade fees. If you're rebalancing quarterly, choose a platform with free or cheap rebalancing.
Are you using an ISA or pension? If you're saving for retirement, tax efficiency is huge. Check that your chosen platform supports the tax wrapper you want.
Do you want advice or research? Some platforms offer educational content and portfolio analysis; others are bare-bones. If you'd benefit from reading fund factsheets and understanding risk tolerance, pick a platform with good guidance.

Once you've narrowed down candidates, check the FCA's Financial Services Register to confirm they're regulated.

Red Flags

Avoid any platform that:

Isn't FCA-regulated. This is non-negotiable. If it's not on the Financial Services Register, it's not legally authorised to hold your money.
Won't disclose fees upfront. If you can't see a clear fee schedule before opening an account, walk away.
Has suspiciously cheap fees with hidden catches. "Free trading!" sounds great until you discover the bid-ask spread is 2%, or there's a £150 inactivity fee if you don't trade every six months.
Offers guaranteed returns. No legitimate investment platform guarantees returns. If they promise one, it's a scam.
Doesn't segregate client money. Your money should be held in a separate bank account from the platform's own funds. This is an FCA requirement you should be able to verify in the terms.

Most major UK platforms (Vanguard, Fidelity, AJ Bell, Nutmeg, Wealthify) are solid. The differences are nuance, not night-and-day. Pick one that fits your fee situation and features, open an account, and start investing. The cost of delaying by six months while you perfect your platform choice is almost always higher than the fee difference between good options.

Worked Example: Which Platform for £15,000?

You have £15,000 to invest for the long term. You're not trading stocks — you want a diversified fund portfolio. You're tax-conscious and want to use your ISA allowance.

Option A: Flat-fee platform (£120/year)

Cost: £120 in year one (0.8% of your portfolio)
Pros: Simple pricing, good for small portfolios
Cons: As your portfolio grows, percentage fees become cheaper

Option B: Robo-advisor (0.5% per year)

Cost: £75 in year one
Pros: Automatic rebalancing, diversified portfolio, lower cost on smaller amounts
Cons: Less control over individual holdings

Option C: Full-service broker (0.75% fee)

Cost: £112.50 in year one
Pros: Wider investment choices, can pick individual funds

The robo-advisor wins on cost (£75 vs £120 vs £112.50). But if you like to research funds yourself and find automatic rebalancing unnecessary, the flat-fee platform might suit you better.

The point: do the maths for your specific situation. Don't just pick what's "cheapest" in the abstract. A platform that costs £50/year but charges per trade might end up more expensive than one charging £120/year with free rebalancing.

Frequently Asked Questions

Q: Should I use different platforms for different investments? A: You could, but it's usually unnecessary. Most modern platforms support ISAs, general investment accounts, and pensions all in one place. Spreading money across five platforms means five login credentials, five fee schedules to track, and five times the admin. Unless a specific platform is exceptional for one investment type, consolidate.

Q: Can I move my money between platforms? A: Yes. You can transfer holdings in-specie (move the fund/shares themselves) or sell and reinvest. In-specie transfers are cleaner because you don't trigger a capital gains tax event. Some platforms charge an exit fee; check before transferring out.

Q: Does platform choice affect my tax bill? A: The platform doesn't create tax liability, but it affects how efficiently you can use tax wrappers. A platform that doesn't support ISAs makes it harder to shield growth from tax. A platform with high fees for pension contributions discourages saving enough for tax relief. So yes, the right platform choice can reduce your tax bill indirectly.

Q: What if I start with a flat-fee platform, then want to move to a percentage-based one? A: You can transfer your holdings once your portfolio is large enough for percentage fees to make sense. Most people's crossover point is £20–30k. Before that, stay with flat-fee; after, switch if it saves money. Transfers usually cost £10–30, so don't let switching costs stop you from moving to a better option long-term.

Q: How do I know what return to expect? A: What counts as a good investment return depends on your time horizon and risk tolerance. Globally diversified equity portfolios have historically returned 7–10% per year over 20+ years; bonds return 4–5%. Your actual return depends on what you invest in, not the platform. The platform just holds your stuff.

Q: Should I invest in individual stocks or funds? A: For most people, diversified funds are better than picking individual stocks. Funds give you exposure to dozens or hundreds of companies with one purchase, reducing the risk that one bad pick tanks your portfolio. If you enjoy stock research and have 10+ years to invest, individual stocks can work. But start by understanding your risk tolerance first.

Q: What if I want a ready-made portfolio? A: Robo-advisors (Wealthify, Nutmeg, Vanguard Personal Advisor Services) build and rebalance a diversified portfolio based on your risk profile. They charge 0.25–1% per year and require minimal effort. For longer-term planning, see how you'd approach building a retirement income plan.

Q: Is it ever worth paying for financial advice instead of using a platform alone? A: For portfolios under £50,000, independent advice typically costs more than it saves. For larger portfolios or complex situations (inheritance, business sale, pension decisions), professional advice can be worth it. Most advisers charge 0.5–1.5% per year or a fixed fee. Compare the cost of advice against the value of optimising your tax, pension contributions, and portfolio rebalancing.